Adjustable contact finger



June 13, 1933. w E s n- 1,913,617

ADJUSTABLE CONTACT FINGER Filed Aug. 13, 1932 INVENTOR. William E. Smith BY 4mm HIS ATTORNEY.

iorming part of the finger illustrated in Patented June 13, 1933 PATENT OFFICE mun: E. smrn, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR 'ro THE UNION PE NSYL AN swrroHl & SIGNAL contrary, or sWIssvALE, PENNSYLVANIA, A, oonPoRA'rIoN or ADJUSTABLE CONTACT Application filed August 13, 1932. Serial No. 628,685.

My invention relatestoadjustable contact ers. ontact fingers embodying my lnvention are particularly suitable for, although in no waylimited to, use in circuit controllers of the drum type in which contact bands or segments are attached to 'a rotatable member in any one of a plurality of positions eachspaced a predetermined angular d stance apart, and in which it is desirable to be able to complete electrical circuits in angular positions of the rotatable member falling between those which can be obtained 'by varying the positions of the bands on the rotatable member.

II will describe one form of contact finger embodying my invention, and will then polnt out the novel features thereof in clalms.

"feln the accompanying drawing, Fig. 1 is a View, partly in side elevation and partly sectioned, showing one form of contact finger embodying my invention, applied to a circuit controller of thedrum'type. Fig. 2 is a side View ofthe member 3 formmg part of the finger illustrated in Fig. 1. Fig. 3 isa top plan view of the member 3 forming part of "the finger illustrated in Fig. 1. Fig. 4 is a top plan view of the contact block 5 forming part. of the finger illustrated in Flg. 1. Fig. 5 is a .top plan view of the locking ring 8 iorming part of a circuit controller of the drum type, which roller is adapted to be rotated about its longitudinal axis through any angle. that may be desired. The roller R isof insulating material and carries a contact band 1. This contact band maybe secured to the rol'ler in any preferred manner, but as hereshown, it isseeured to the roller in a selectedoneof a plurality ofvpositions each spaced a predetermined angular distance apart, byflbending down ,the ends of the band ,gnd insertingthe ends thus bent down into longitudinal slots 2 Whichare out into the surface of the roller ,for the purpose of tightly gripping the endsiof the band to hold the band firmly in place in the desired position.

Cooperatingwith the contact band 1 is an adjustable contact finger F embodying my invention. :As here. shown, this contact .fin-

comprises, in general, a. suitable support- ,ingniember 3 having journalled therein an ad usting screw 4, upon which a'contac bl ck 5 is mountedin such manner that it will move along the axis of the adjusting screw lnresponse to rotation of the screw. The

supporting member 3, in theforin here by means of an integral ;L-shaped ofi'set por" tion 3 The ,heel portion 3 is ,apertured to receive a terminal post 6 by means of which thestri-p may be attached to a suitable insulating terminal board 7; The oneleg 3 of the L-shaped offset portion?) is disposed atan obtuseangle with the main part of the strip, and is provided with a hole 3 which receives the adjusting screw with some clearance at a nonrthreaded portion 4 of reduced diameter formed on the lower end of the screw, The other leg 3 of. the L-shaped-offset portion?) extends parallel to the adjustingscrew 4 in spaced relation thereto, and cooperates with a longitudinal slot 5 (see 4) formed in the sideof the contact block 5 to prevent the contact block from turning when the adjusting screw'is rotated, as will be readily understood from an inspection of the drawing. The U-shaped portion 3 of the strip 3 is so disposed that both of its sidesextend substantially parallel to, and in vertical alignment with, the leg 3 of the L-shaped portion 3 when the parts are assembled, as shown in 'Fig. 1, but beforethe parts are assembled, the upper side of this -U- shaped portion is inclined away from the lowerside ataslight angle, as shown in Fig. 2, the reason for this being made clear presently. Provided in the Ushaped portion 3 is a slot 3 (see Fig. .3), which slotv extends into both sides of the U-sha (1 portion at their joined ends and whic aligns at its innerend with the hole 3. This slot r6- cei yestheadiusting screw 4 at a turned-down of reduced diameter formed bep i p .i Qshoulder an r -i1 I a V IEle parts aregogcportioned that when the ere: 2612?? new 4 s i s t 1 p V i h. pedportionfl" be omedtothe po- 7, T'sition in which it is suhstantially parullel to Y lower side, thus causing the sides of the {U-shaped portion to enert a frictiona .iorce. k 'M-Mpnthe ad usting screw which prevents uns 1 g f Thc'j adjusti w ee F1 lssunbledifihto tamed own if I; 1* T V Y i r toretai'n it WM Sig-oi course,

m "reccivef 'the admstmg H a. mm aiwiirh hh hm rwihh this 0011- that sinej rotatien of the contact efitcki sahpehsew shiihh 0i thhhajusiih I ted flieslbtfi? in thebloc :6 .i wi h [.fle 3 oithe L-shaped the adiusting screw block to move up- -along the axis of t 'e L g V i i. i the directionin which I 'wsercwiis 7 I iIt-will alsobeapparent 'flitwhtn the-contact block is moved u idovmm'tiirdlytalong the-axis of e the. -'Pb8ifi0h$ ofgthe roller R the formed by contact I p n h mmt blo k 5becbme owl. 5 *Bww t s this ewlto ihectmciclpsedfindiflerent an lar i iof the refiethom that whic even be n iiiafimfitonthetfinger were proot the adjustable contact fin- .4 fmy i'nvcntion. Inorderfio contact will be i i i i 1} k #"thc 3 and the I agportioiroffthe leg n' is toward the is we whisk mi tlie 'n hlock he bottom of the though I W- herein shown and deof adjustable contact i aembodfiiigqmywinventmn, it is underand modifications f ff wzthin th s scope of the m departing from the invention. iii r i bsdmy invention; what v (I h e @wec-fingm re p m edjossing scroifa' stri of resi ient -fiiducting'matsinhhbent to orm ortions irhi'ell' act asbeeiingsior said a justing New; end 4 min block screwed onto said Mr- 'mi adjusting screw and provided with means: which cooperates with said strip to cause said 7 block to move along the axis of said ing screw in response to rotation of-scidigi, ad usting screw. T

eiius i iiis stripof resi' provided with an L shaped y isht in ei n portion, the 'sides of w ch exfien tially parallel to and in l of said pfiset portionfsiud one leg siid a 0 set portion being provided ith 2 11010 and, said U-shaped ipont'fim b 1 I with a slot extending into its m: at g closed ends, an adjusting screm'ii n'v fic; ortion adjacent the head of the nalled' in the slot'insaid U-shzi and af ,ortion atitsop ite e f; in the '01s in said one eg of said tion'; an annular fleng efiormed onslidsbc'raw on the opposite sided saidilb a. :tiomfrom sedil i'ieadfuv ringisurro screwbetweenthe sidesoisaid U-shn tion to hold saidlscreiz inplaceiin- (T she d portion,a contlctblocbmruvedom A sai adjusting screw; andmeuisiior venting rotation of said conte'et blocki'm response to rotation of .said adjusting 831i! QI while permitting movement of said blockalon the IXiS 0f 8lidscrew i' niii ti I 3. An 2 jnstable contact ing a;strip of resilient conducting. i

end b L h d fise hm tion an -s ape o t portion; one leg extending parallel to and in f t ment with the sides of said uhoped tionand at an obtuse a e with portion, said oneiieg provided;

a hole and said uishapcd portion viziied gvithdii,J silo; 'wiich extends-into .si eso sai -s pe rtienntfl ends and which slot agns at its withasaid' hole, a mfew having MW down portion adjaaefl itsihecdk in said slot and. anoflieritumed: tionlat its oppositeendiournfilcdzim hole, a ring surrounding the portion of said screw betwee h lid: oflset p t n to in t mid 'p s vi sa m, and eis liwt 8 onto said screw between l k i portion the sides of which extend substantially parallel to and in alignment with one leg of said ofl'set portion, said one leg of said oflset portion being provided with a hole and said U-shaped portion being provided with a slot extending into its sides at their closed ends, an adjusting screw having a portion adjacent the head of the screw journalled in the slot in said U-shaped portion and a portion at its opposite end journalled in the hole in said one leg of said offset portion, an annular flange formed on said screw on the opposite side of said U-shaped portion from said head, and spaced from said head such a distance that the sides of said U-shaped portion will frictionally engage said screw at said head and said flange to prevent undesired turning of said screw, a ring surrounding said screw between the sides of said U-shaped portion to hold said screw in place in said U-shaped portion, a contact block screwed onto said adj Listing screw, and means for preventing rotation of said contact block in response to rotation of said adjusting screw while permitting movement of said contact block along the axis of said screw.

5. An adjustable contact finger comprising a strip of resilient conducting material bent to form a heel portion'at one end which extends at an acute angle with the body of the strip and a U-shaped portion at the other end which is connected with the body portion by an L-shaped offset portion having one leg extending parallel to and in alignment 3 With the sides of said U-shaped portion and at an obtuse angle with said body portion, said one leg being provided with a hole and said U-shaped portion being provided with a slot which extends into both sides of said 40 U-shaped portion at their joined ends and which slot aligns at its inner end with said hole, a screw having a turned-down portion adjacent its head j ournalled in said slot and another turned-down portion at its opposite end journalled in said hole, a ring surrounding the turned-down portion of said screw between the sides of said ofl set portion to fasten said screw in place in said slot, a contact block screwed onto said screw between said U-shaped portion of said strip and said one leg of said offset portion and provided with a slot which slidably receives the other leg of said ofi'set portion, and a tongueprovided on said other leg of said L-shaped ofiset portionand bent into frictional engagement with said contact block to insure good electrical contact between said contact block and said strip.

In testimony whereof I aflix my signature. WILLIAM E. SMITH. 

